Speed-change mechanism



Feb. l,l 1903.8. K F GALLlMORE 2,106,731

SPEED CHANGE MECHANISM Filed Aug. 9,' 1934 2 Sheets-Sheet l Patented Feb. l, 1938A OFFICE en Mechanism Keith F. nainmore, rend au Lac, wis., signor to Giddings & Lewis Machine Tool Co., Fond du Lac, Wis., a corporation of Wisconsin Application August 9, 1934, Serial No. 739,076

Claims.

The present invention relates to improvements in speed-change mechanisms, adapted particularly for machine tools.

One of the objects of A thepresent invention resides in the 4provision of a speed-change gear mechanism having a novel crank-type adjusting means.

Another object is to provide'new and improved gearv shifting means which is simple in construction and operation, and which necessitates but a relatively small number of parts and operating members.

Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a fragmentary front elevational view of a mechan ism embodying the features of my invention.

Fig. 2 is a fragmentary vertical sectional view taken substantially along line 2--2 of Fig. l.

Fig. 3 is a fragmentary detail sectional view taken substantially along line 3,-3 of Fig. 2, and illustrating two intermittent gears.-

Fig. 4 is a. fragmentary sectional View onv an enlarged scale taken substantially along line l--t of Fig. 1.

Fig. 5 is a fragmentary sectional view on an enlarged scale taken substantially along line 5--5 of Fig. 2, and illustrating the operation of the gear shifting means.

Fig. 6 is an elevational view of a dial for indicating the adjustment of the mechanism.

Fig. l is a fragmentary view of a development of a speed-change gearing forming part of the .mechanism.

Referring more particularly to the drawings, the speed-change mechanism may be interposed in any desired drive, for example a rotative spindie drive or an axial-feed spindle drive, as disclosed in the `patent to Gallirnore No. 1,858,491, issued May 17, 1932, and may be adapt/ed to afford any desired number of selective speeds.

In the present instance, the mechanism (see Fig. 7) is illustrated as comprising a nine speed gearing 8, which in effect comprises two threespeed gearings. and one two-speed gearing 9, connected in series to provide eighteen different available speeds. closed Within a. suitable casing I mounted for adjustment along parallel guideways II (one not shown) by means of a feed screw I2.

'Ihe nine-speed gearing 8 comprises an inlet shaft I3, an outlet shaft I5, and an intermediate shaft I4, all of said shafts being suitably journaled in the casing l0. The inlet shaft I3 is adapted to be connected to 'a suitable source These gearings may be en- (Cl. 'I4-473) for axial adjustment on the inlet shaft I3 between the gears 22 and 2t, and has clutch elements 21 and 28 on opposite sides adapted to coact respectively with the elements 25 and 26.

- The gear 23, with the clutch elements 21 and 28, constitutes a. shift-,able clutch unit having three different operative positions of adjustment for connecting the shafts I3 and respectively through the gears 22 and I1, 23 and I8, and 24 and I9. These various gear combinations have diierent speed ratios so that the intermediate shaft Ill may be driven selectively at any one of three different speeds. In the present instance, the speed ratios decrease progressively in one direction. Thus, the ratios from left to right may be 19 to 37, 22 to 33, and 25 to 30.

Two gears 29 and 30, formed respectively on their adjacent sides with clutch elements 32 and 33, are freely rotatable on the outlet shaft I5, and mesh continuously with the' gears 20 and 2l on the intermediate shaft I4. gear 3l is splined for axial adjustment on the outlet shaft i5 between the gears 29 and 30, and has clutch elements 513 and 35 on opposite sides adapted to coact respectively with the elements 32 and 33.

The gear 5I, with the clutch elements 34 and 35, constitutes a shiftable clutch unit having three different operative positions of adjustment for connecting the shafts M andl I5 respectively through the gears 2@ land 29, 2l and 30, and' I8 and 3l. AThese gears combinations have progressively decreasing speed ratios, for example to 40, 24 to 32, and 33 to 32, for driving the shaft I5 at any one of three different speeds from the intermediate shaft I4. f

-By adjusting each ofthe clutch umts 23 and v3i Vsuccessively into positionsof progressively lower speed ratios, and adjustingone unit, for example the unit 23, through all of its positions for each position of the4 other unit, the outlet shaft I5 'may be driven at nine progressively increased speeds.,

The two-speedl gearing 9 is connected tothe shaft I5. and comprises an outlet shaft 3. and

An intermediate a back shaft 31. Fixed on the shaft I5 is a gear 39 having a clutch element 39 on one side, and meshing with a gear 49 xed on the back shaft 31. Another gear 4|, fixed on the back shaft 31 vin axially spaced relation to the gear 49, meshes with a gear 42 which is splined for axial adjustment on the shaft 36, and which has a clutch element 43 on one side for cooperative engagement with the element 39. The gear 42 constitutes a shiftable clutch unit for-connecting the shafts I5 and 36, either directly Vthrough the clutch elements 39 and 43 at the same speed, or indirectly through the gears 39, 49, 4| and 42 at a relative speed,` for .example at a ratio of 8 to 1.

A shifter shoe 44 which is slidably supported on a rod 45 (Fig. 2) for rectilinear adjustment along the shaft I3, engages opposite sides of the clutch unit 23, and is'adapted to move the latter into any one of its three positions of adjustment. The shoe 44 has a. laterally extending pin 46 which projects into a notch 41 in the lower end of a vertical lever 49. 'I'he upper end of the'lever 43 is xed ony the rear end of a forwardly extending rock shaft 49 journaled in bearings 53 and 5| in the casing I9. A depending lever 52 is fixed at its upper end on the forward end of the shaft 49. The levers 49 and 52 vserve to conne the rock shaft 49 against end-v wise movement.

The lower end of the leverv 52 has an enlarged head 53 (Fig. 4) formed with Aa generally longitudinal cam groove 54. An eccentric crank pin 55 mounted 0n the inner end of a crank shaft 56 extends operatively into the groove 54. The shaft 56 is journaled in a bearing51 in the rear wall of a casing 53 closing an opening 59 in the front wall of the main casing I9. A removable cover plate 69 closes the front of the casing 53. 'Ihe forward end of the shaft 56 extends through the casing v53, and is provided with an operating lever 6| at the front of the cover plate 63.

Upon rotation of the shaft 56, the crank pin 55, through coaction with the sides of the cam groove 54, will oscillate the lever 52,'through a predetermined range, to shift the clutch unit 23. In the present instance, the crank pin 55 has three operative positions spaced 120 -degrees apart, and identiied by the characters A, B and C (Fig. 5). Opposed clearance recesses or -grooves 62 and 33 are formed in opposite sides of the cam groove 54. In position A, the crank pin 55 engages the lower edge of the recess 62, thereby establishing the lever 52 in its extreme left-hand position to connect the clutch elements 25 and 21. This position is occupied for the first, fourth and seventh speed adjustments of the nine-speed gearing 3.

position B at the upper end of the groove 54 with- -out calling over-travel of the lever 52 to the left.

In position B, the lever 52 occupies an-intermediate position to establish the gears I3 and 23 in meshing engagement for the second, fourth and 'I'he clearance re .'cess 32 permits movement of the pin 55 into the -shaft 66 (Fig. 1).

operated thereby are returned in one continuous rotatably secured at its upper end on the forward end of the shaft 49 (Figs. 2 and 5).. The lever 65 is provided intermediate its ends with an enlarged head 66 formed with a longitudinal cam groove 61 similar to the groove 54. An eccentric crank pin 68 on the inner end of a shaft 69, extending through and journaled in the casing 59, projects into operative engagement with the groove 61.

Upon rotation of the shaft 69 in a counterclockwise direction, the pin 68 will be revolved successively into operative positions D, E and F in which connections will be established respectively between the clutch elements 32 and 34, the clutch elements 35 and 33, and the gears |8 and 3|. Clearance grooves 10 and 1| avoid over-travel of the lever 65 beyond its end positions. first, second and third speed adjustments, the

position E for the fourth, fifth and sixthspeed adjustments, and the position F for the seventh, eighth and ninth speed adjustments, of the ninespeed gearing 8.

Means is provided for rotating the crankshaft 6 9 through 120 )degrees once for each complete rotation of theshaft 56. This means preferably comprises two K intermittent gears 'I2 and 13 (Figs. 3 and 4) fixed respectively on the shafts 56 and 69 inthe casing 59. The gear 12 has a toothed section 14 extending through 120 degrees, and adapted to mesh successively with three similar toothed sections 15, 16 and 11 on the gear 13 during recurrent movements of the pin 55 between positions A and C. Abutments 13 separating the toothed sections 15, 16l

and 11 lon the gear 13 are movable selectively into engagement with the untoothed portion of the gear 12 to lock the gear 13 in fixed position during movement of the pin 55 between the positions A an`d B, and B and C.

To provide means for adjusting the two-speed gearing 9, a shoe 19 (Figs. 2 and 5) is pivotally mounted on the lower end of a crank arm 39, land engages opposite sides of the clutch unit 42. The crank arm is xed on the inner end of avrock shaft 9| journaled in a cover plate 92 on the front of the casing I0, and provided on its outer end with a hand lever 93.

It will be evident that upon rotation of the shaft' 56 in a clockwise direction, the gearing 9 will be adjusted to obtain a sequence of nine different vspeeds of progressively increasing values. When the two-speed gearing 9 is closed through the back shaft 31', thesev nine speeds,

-on. the basis of the present gear ratios, are repretimes the composite adjustment of the gearings- 3 and 9, the two foregoing series of speed indicia are placed in two concentric rows on the face of a rotary dial 34 (Fig. 6). The latter is secured against one side of a gear which is mounted 1 for rotation on a projection 96 within the'casing 53 (Fig. 4), and which meshes with a gear 91 on A sight opening 99 is The pin 68 occupies 'position D for the` formed in the cover 1plate 69 to extend across the 75 gaging said element, an oscillatory lever having l two rows of indicia on the dial 84 `so that the' associated pairs of indicia corresponding to the various adjustments of the gearing 8 will be selectively exposed to view.

' Extending into one side of the casing 58 between the cover plate 6D and the dial 84 is a slide bar 89. The outer end of the bar 89 has a pivotal connection with the lever 83. The inner end of the bar 89 has a sight opening 90 in registration with the opening 88, and movable selectively into position over the particular row of indicia on the dial ad representing the adjustment of the twospeed gearing 9.

I claim as my invention:

l. A speed-change mechanism comprising, in combination, a speed-change gearing havinga shiftable gear element, a shiftable shoe engaging said element, a rock shaft, la lever iixed at one end on said shaft and having a' pin and notch connection at the other end with said shoe, a second lever nxed at one end on said shaft and formed with a generally longitudinal cam groove, a crank shaft having an eccentric crank pin on one end projecting transversely into said groove, and means for rotating said crank shaft, whereby said rock shaft will be oscillated to shift said element in opposite directions, said cam groove having clearance recesses formed in the sides thereof for preventing over-travel ofsaid shiftable gear element. v

2. A speed-change mechanism comprising, in

combination, a speedchange device having a reversibly adjustable element, a rockeshaft, a lever fixed on said shaft and having an operative connection with said element, a second lever xed yon said shaft and formed with a generally longitudinal cam groove, a crank shaft having a crank pin projecting transversely into said groove, and means for rotating said crank shaft whereby said rock shaft will be oscillated to adjust said element, said cam groove having clearance recesses formed in the sides thereof for preventing'overtravel of said element.

3. A speed-change mechanism comprising, in combination, a speed-change device having a reversibly adjustable element, a shiftable shoe enan operative connection with said shoe and formed with a generally longitudinal cam groove, a crank shaft having a crank pin projecting transversely into `said groove, and means for vrotating said crank shaft,.whereby said lever will be oscillated to adjust said element in opposite directions through a predetermined range, said cam groove being contoured to provide a plurality of Vinwardly disposed surfaces contacting with said crank pin to position said oscillatory lever and associated shiftableshoe in selected positions. said surfaces being separated by.A clearance spaces whereby said lever will be oscillated only within said predetermined range of movementand over-travel thereof prevented.

4. A speed-change mechanism comprising, in

. combination, a speed-change device having an adjusting element with three operative positions,

a reversibly movable member operatively con- 4 nected to said element for adjusting .the latter and having a cam grocve,'a revolvable crank pin extending laterally' into said groove and having three operative positions spaced degrees apart and of which two positions define opposite end adjustments of said element and the third posij' tion denes an intermediate adjustment of said element, and clearance 4recesses formed inthe sides of said groove for preventing over-travel of said member upon movement of said pin between said third position and either of said two positions.

5. A'speed-change mechanism comprising, in

combination, a speed-change device Vhaving an adjusting element, a reversibly movable member operatively connected to said element for adjusting the latter and having a cam groove, a revolvable crank pin extending operatively into said groove, and clearance recesses formed in the sides of said groove for preventing over-travel of said member.

, 6. A speed-change mechanism comprising, in combination, a casing, a speed-change gearing in said casing and havingtwoselectively shiftable gear elements, two shifter shoes respectively engaging said elements, a rock shaft journaled in said casing and extending transversely of the direction of movement of said elements, a lever xed on said shaft and having a pivotal connection with one of said shoes, a second lever pivoted on said shaft and having a pivotal connection with the other of said shoes, a third lever fixed on said shaft and extending vat an angle to said second lever, said second and third levers being vformed lrespectively with generally longitudinal cam grooves, two crank shafts vjournaled in said casing and parallel to said rock shaft, two eccentrically disposed crank pins on the ends of said crank shafts and projecting respectively into said cam grooves, and means for rotating saidcrank shafts.

'1. A speed-change mechanism comprising, in combination, a casing, a speed-change gearing in saidcaslng and having two selectively shiftable elements, two shifter shoes respectively engaging said elements, a rock shaft journaled in said casing and extending transversely of the direction of movement of said elements, a lever' xed on said shaft and having a positive pivotal connection with one of said shoes, a second lever' pivoted on said shaft and having'a positive pivotal connection with the other of said shoes, a

' said crank shafts, and intermittent drive means connectingsaid crank shafts for rotating the other of said crank shafts through a fractional turn for each complete rotation of said one crank shaft.

8. A speed-change mechanism comprising, in combination, a casing, a speed-change device in said casing and having two selectively adjustable tively to said elements, said levers being formed respectively with generally longitudinal cam grooves, two crank shafts journaled in said casing and having crank -pins projecting respectively into said cam grooves and operable upon being revolved and through coaction with the sides of said groovesto oscillate said levers, means for rotating one of said shafts, and intermittent drive means connecting said shafts for rotating the other of saidshafts through a fractional turn for each complete rotation of said one shaft.

9. A speed-change mechanism comprising, in

, so' elements, two pivotally mounted independently oscillatory levers operatively connected respeccombination, a. ninespeed gearing having two 75 adjusting elements movable in parallel directions and each having two end positions and an intermediate position of adjustment, two levers operatively connected to said elements and oscillatory in directions parallel to said first mentioned directions and each being formed with a cam groove having a component extending longitudinally thereof, two parallel crank shafts extending perpendicularly to said levers and having crank pins projecting respectively into operative engagement with said grooves, an intermittent gear on one of said shafts and having three gear sectors each extending through 120 degrees, an intermittent gear on the other of said shafts and having a single gear sector extending through 120 degrees for selective meshing engagement with said first mentioned sectors to rotate said one shaft through one-third revolution once for each complete revolution of said other shaft, and means for rotating said other shaft.

10. A speed-change mechanism comprising, in

aioavai combination, a speed-change gearing having two adjusting elements, two plvotally mounted oscillatory levers operatively connected to said e1e.

ments and each being formed with a cam groove having a component extending longitudinally thereof two parallel crank shafts extending perpendicularly to said levers and having crank pins projecting respectively into operative engagement with saidgrooves and operable'upon being revolved and through coaction with the sides of said grooves to oscillate said levers, an intermittent gear lon one of said shafts and having a plurality of gear sectors. an intermittent gear on the other of said shafts and having a single gear vseotor for selective meshing engagement with said first mentioned sectors to rotate said one shaft through a fractional revolution once for each complete revolution of said other shaft, and means for rotating said other shaft.

' KEITH F. GALmMoRE. 

